Daniele Licciardello | Searcharxiv

arXiv2026

Non-invertible symmetries in the axiverse, and the imaginary wormholes

We study the symmetry structure of four-dimensional axiverse effective field theories with multiple axions coupled to abelian gauge sectors, including their extensions to broad classes of N=1 models. We identify the invertible and non-invertible generalized symmetries, and discuss the associated symmetry-breaking mechanisms together with the resulting hierarchies of energy scales. In particular, we discuss the quantum-gravitational breaking of non-invertible axion shift symmetries predicted by the existence of wormholes and the recently proposed Imaginary Distance Bound. In N=1 axiverses, these wormhole-based arguments imply that towers of BPS EFT instantons play a distinguished role and generate infinitely many superpotential terms.

hep-th↗

arXiv2026

Extending the Dynamical Systems Toolkit: Coupled Fields in Multiscalar Dark Energy

We study the dynamics of a two-field scalar model consisting of an axion-saxion pair with both kinetic and potential couplings, as motivated by string theory compactifications. We extend the dynamical systems (DS) toolkit by introducing a new set of variables that not only close the system and enable a systematic stability analysis, but also disentangle the role of the kinetic coupling. Within this framework we derive a compact, general expression for the non-geodesicity (turning-rate) parameter evaluated at fixed points, valid for arbitrary couplings. This provides a transparent way of diagnosing non-geodesic dynamics, with direct applications to both dark energy and multifield inflation. We first consider exponential coupling functions to establish analytic control and facilitate comparison with previous literature. In this case, we uncover a pair of genuinely non-geodesic fixed points, which act as attractors within a submanifold of the full system. In contrast, when the axion shift symmetry remains unbroken, our analysis shows that the apparent non-geodesic fixed point reported previously does not persist once the full dynamics are taken into account. Finally, we illustrate how our approach naturally extends to more realistic string-inspired models, such as power-law axion potentials combined with exponential saxion couplings, and present an explicit supergravity realisation.

hep-th↗